1. Field of the Invention
The present invention relates to electronic musical instruments, and in particular, to electronic musical instruments which employ multiple tone generating elements.
2. Prior Art
Sound production by a speaker can generally be considered in terms of sound radiating from a single point and having significant directional properties, whereas in the case of conventional non-electronic musical instruments, the sound produced thereby most often emanates from a three dimensional cavity and/or from one or more two dimensional surfaces with variable directional properties. For example, in the case of a piano, through the action of hammers on strings, a considerably broad sound board is caused to vibrate from which sound radiates in a relatively diffuse pattern. Electronic musical instruments have been conventionally disclosed whereby the effect of a conventional non-electronic musical instrument can be simulated, that is, the effect of sound radiating from a two or three dimensional source having the directional properties of the target instrument is simulated. Examples of this type of electronic musical instrument include that disclosed in Japanese Patent Publication Laid-Open No. Sho61-97698. Waveform data for this kind of device are obtained by producing musical tones using a conventional musical instrument which is to be simulated within an acoustical environment to be simulated, and capturing the produced tones with multiple acoustical sensors spatially distributed at varying distances and positions in relation to the conventional musical instrument. The acoustical data thus obtained from each acoustical sensor is converted to waveform data which is then stored using a suitable memory device or data storage media. By simultaneously reading out the waveform data thus stored and reproducing the sound using multiple speakers suitably arranged, the sound originally produced using the conventional musical instrument can be quite faithfully reproduced.
In Japanese Utility Model Publication Laid-Open No. Sho59-166293, another electronic musical instrument has been disclosed, employing multiple musical tone generating systems operated in parallel, as with the device described above. With this device as well, plural waveform data is stored in multiple memory devices, from which the waveform data is simultaneously read out at a predetermined rate, whereupon signals based thereon are supplied to two or more speakers, whereby the sound of a conventional musical instrument is reproduced.
With the type of conventional devices described above, multiple tone generating and sound producing systems are employed and operated in parallel. Certain situations exist, however, when it is desirable to use only a single tone generating and sound producing system, for example when monaural sound reproduction is desired. The conventional electronic musical instruments described above generally do not permit a single tone generating and sound producing system to be used alone, for which reason these devices are suboptimal in such a case.
Further, to provide capability for monaural sound reproduction, as well as for stereo sound reproduction, or for three or more channel sound reproduction in one device, and to provide the output of each tone generating system to variable number of sound producing systems, a tone generator for monaural sound production and an additional tone generator for multichannel sound reproduction are required, thereby complicating the design and electronic layout of the device.